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‘Bloop’

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In 1997, the National Oceanic and Atmospheric Association detected a low-frequency and high amplitude sound from under the water in the South Pacific Ocean. Despite initial speculations that it was some sort of sea creature, it is now (thankfully) assumed to have been the sound of glaciers moving or breaking.

The Bermuda Triangle

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Since the mid-20th century, the Bermuda Triangle, also known as ‘the Devil’s Triangle’, has fascinated the world. The concept of the Bermuda Triangle relates to the mystery surrounding the unexplained disappearances of a variety of ships and aircrafts. Though the precise location is disputed, it’s considered to be in the North Atlantic Ocean.

Baltic Sea anomaly

Credit: Timeline

The Baltic Sea anomaly has been the source of many wild speculations and theories since the sonar image was taken in 2011 by self-described treasure hunters Ocean X. The image depicts a large, unidentifiable object that seems to resemble the Millennium Falcon, which has given rise to rumors of it being a sunken UFO. Samples also indicated the presence of volcanic rock, which only adds to the mystery.

Ultra-black fish

Credit: Mysterious Worlds

‘Ultra-black’ refers to a shade of black that reflects less that 0.5% of light. In recent years, several species of fish have been discovered with ultra-black skin. It is thought that this feature provides them with camouflage, in addition to preventing light from bioluminescent prey they’ve consumed from being emitted.

Aegean Sea ruins

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The ruins of an Ancient Greek city, including towers, structures, and pathways thought to date back over 4000 years, were discovered in the Aegean Sea in 2015. Archaeologists were able to recover and study more than 6000 artefacts from the ruins. It is thought that they may be the lost city of Kane, famed for its significance during the Peloponnesian War between 431-404 BC.

Adam’s Bridge

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Otherwise known as Rama’s Bridge, Adam’s Bridge is a ‘pathway’ of limestone shoals between India’s Pamban Island and Sri Lanka. Its origins are unknown, however it is suspected that due to its placement and shallow nature, it was once a bridge connecting the two areas.

Black swallower fish

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The black swallower fish is truly the stuff of nightmares. Though the maximum length of a black swallower has been recorded at a mere 25cm, due to its expandable stomach this small fish is able to consume creatures ten times its weight and twice its length. Some are known to eat prey so big that they’re unable to be digested before decomposition.

Mariana Trench

Credit: Natural World Facts

Named after the nearby Mariana Islands, Mariana Trench is the world’s deepest oceanic trench. It is located in the Pacific Ocean, and is over 6 miles deep, with an atmospheric pressure over 1,000 that of the standard sea level. Only 27 people have ever ventured to the deepest part of the Mariana Trench, known as ‘Challenger Deep’.

Milky seas effect

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Mareel, otherwise known as the milky seas effect, is a phenomenon whereby large parts of the ocean adopt a translucent glow. This is caused by bioluminescent bacteria beneath the surface, however the origin of this bacteria and what causes them to congregate in such large quantities is still unknown.

The ‘Jacuzzi of Despair’

Credit: EVNautilus

Uninhabitable to all but a select few, the ‘Jacuzzi of Despair’ is a brine pool located in the Gulf of Mexico, one kilometer beneath the surface. It has a higher temperature and salt content than the rest of the surrounding water, creating an underwater ‘lake’ which attracts sea life. However, with the exception of bacteria and certain types of worms, shrimp, and mussels, the pool is entirely deadly.